I'm a Persian, I'm from Iran, and I speak Farsi. Here, we have a very strange rule that we turn آ into و in informal conversations. For example:

خانه = house (formal) /kh a ne/
خونه = house (informal) /kh u ne/

In other words, we mutate a sound based on formality.

I don't know the name of this phenomenon. And I also wonder if we have something similar in English or not?

  • 1
    I wonder... would shortening "want to" to "wanna" and "going to" to "gonna" etc. count?
    – Llewellyn
    Oct 17, 2020 at 22:10
  • perhaps "Sire" vs. "Sir"? Oct 18, 2020 at 12:30
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    If you said "khune" and someone didn't understand you, and asked you to repeat yourself, would you say "khune" or "khane"? Oct 18, 2020 at 15:39
  • @AzorAhai--hehim, that has never happened I guess. but in case it happens, my first response would repeating "khune" assuming they have not heard me. I mean it's so understandable that I can't think of "not umderstanding" as the cause of misunderstanding. but after a couple of tries, yeah I would fall back onto "khane" Oct 20, 2020 at 7:34
  • Not misunderstanding like they don't know what the word is, but like over a phone and they didn't hear. Oct 20, 2020 at 13:19

4 Answers 4


The shift of classical Persian ān to ūn is a feature of Tehran dialect (Tehrūnī), and of many other forms of colloquial Persian. It is an example of “labialization”. This phenomenon is widespread in languages of the world; we have it in English when we write “all” but pronounce it like “awl”.

  • 3
    To be clear for the OP, "awl" isn't an informal pronunciation of "all." It's an example of the same sound shift. Oct 17, 2020 at 22:02
  • I have no idea how house "formal or informal" could translate into English. Is this to do with "house" and "home" or what? Oct 17, 2020 at 22:54
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    @RobbieGoodwin My guess is that not so much "formal" vs. "informal" as it is "classical" vs. "colloquial".
    – No Name
    Oct 18, 2020 at 3:11
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    @RobbieGoodwin The word for ‘house’ was originally /xɑːne/, which in most standard variants of Modern Persian is now /xɒːne/, with a rounded back vowel. In some dialects, particularly Tehrani, and especially in colloquial registers, /ɒː/ has been raised first to /oː/ and then all the way to /uː/ before nasals, so /xɒːne/ is now /xuːne/, /iɾɒːn/ (Iran) is /iɾuːn/ and /tehɾɒːn/ is /tehɾuːn/. It’s not that they have different formal and informal words for ‘house’, but that the word is one of many that has a more formal and a more colloquial possible pronunciation. Oct 18, 2020 at 18:27
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    Is "labialization" really the usual term for this? The change seems to go from an unrounded low back to a rounded high back vowel, so there's clearly more involved than just lip rounding (which "labializaiton" might refer to).
    – Schmuddi
    Oct 19, 2020 at 6:34

I don't know Persian, however I have some knowledge of linguistics. The example given seems to be linked to a shift in register (different use of language in different circumstances). The formal form is 'greater effort'; the informal form is 'lower effort' / more relaxed, which here is a shift from the higher pitched 'a' sound to the lower pitched 'u' sound.

In the example given, this seems to be a semi-generalised rule for this particular sound. I'm not sure if English has similar semi-generalised rules, but something slightly similar would be the general use of contractions. To some people, contractions are a marker of informality and should not be used in highly formal speech or writing.

  • 'will not' vs 'won't'
  • 'can not' vs 'can't'
  • 'should not' vs 'shouldn't' (I avoided using 'shouldn't' in the above paragraph)

In general, contractions are dropping or altering specific sounds, which seems to fit with the original poster's request. As well as contractions, some other examples of shifts in register are:

  • 'want to' vs 'wanna'
  • 'going to' vs 'gonna'
  • 'yes' vs 'yeah'
  • 'no' vs 'nah'

You will note that the informal form is often 'less effort' than the formal form.

However, be careful not to label it 'lazy' or 'incorrect'. Often the formal form is regarded as 'formal' because it is the type of language (dialect) used by the power group in that culture. Formal language is often used as a tool to exclude others from membership in that power group, or to mark out membership / signify access to education / parentage / etc.

Sometimes the use of a differing dialect is deliberate to signify that the speaker refuses to participate in what they see as an unjustified power structure. (Or to signify membership in a different social grouping.)


In Arabic this practice is called "ibdal" (which means conversion) (ابدال).

In Persian the same name is used because:

  1. Persian has borrowed so many words from Arabic.
  2. Ibdal is also a Quran reading technique in the Muslim world (where 'n' before 'b' turns to 'm'). Since Iran is also a Muslim country they use this name to refer to the technique.

** I know this from a bunch of Iranian friends.

Another example: انبه (Anbeh) which means mango, turns to امبه (Ambeh) in spoken Persian language.

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    Changing /n/ to [m] before labials is a completely different thing. That’s nasal assimilation, and it’s found in virtually all languages around the world, including English. Sep 12, 2023 at 13:43

Though I'm not a linguist, I studied Uyghur and other languages of central Asia for a few years. It sounds like you are describing vowel rounding. Other regional languages such as Uyghur, Kazakh, Turkmen, and others have clear rules for vowel rounding and rounding harmony.

Although vowels in English might be described as rounded or unrounded, it doesn't have the same kind of structures for deciding when a vowel should be rounded or unrounded. For example, words with unrounded vowels don't need to be rounded to become informal, and conjugation won't result in rounded vowels.

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